• Electronics and Telecommunications Trends
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• v.36 no.6
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• pp.36-45
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• 2021

As the global demand for satellite IoT services using small satellites increases, interest in their frequency requirements has also increased. Consequently, International Telecommunication Union Radiocommunication Sector (ITU-R) preparatory studies for WRC-23 include AI 1.18, which considers new frequency allocations for narrowband mobile satellites. This agenda item was issued in accordance with Resolution 284 (WRC-19), and contributions and reviews by government and satellite operators are underway at ITU-R SG4 WP4C with the aim of completing the study in 2023. Resolution 248 (WRC-19) considers the conditions for transmission of candidate bands and satellites and terminals for narrowband mobile satellite, and all contributions should satisfy narrowband mobile satellite system characteristics parameters within these conditions. However, among the current transmission specifications, there are several views on the exact definition of satellite e.i.r.p., and the derivation schedule of characteristic system parameters for the study is slower than that of the original work schedule. The goal of this paper is to examine the outline of WRC-23 AI 1.18 and the main content of Resolution 284 (WRC-19) and to determine the status of studies related to WRC-23 AI 1.18. The ITU-R's study on this agenda includes updating work schedules, developing the draft required spectrum and system characteristics parameter reports/recommendations, developing draft CPM reports, and examining the various views of transmission specifications in Resolution 284 (WRC-19). Focusing on candidate bands in Region 1 (Europe and Africa) and Region 2 (America), the current status of use in Korea is investigated and future countermeasures in Korea are investigated. In addition, we would like to examine the trend of narrowband mobile satellite through satellite frequency and service status and planning of satellite IoT operators, such as EchoStar, Omnispace, and Sateliot that are participating in the ITU-R study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.801-809
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• 2023

Road construction projects have a long duration so cost overruns and schedule delays are occurred. However, performance assessment system that can manage and prepare for this in advance is insufficient. In addition, road construction are affected by many factors during under construction. Therefore it is necessary to conduct performance assessment considering the characteristics of roads and prepare for similar projects in the future. The purpose of this study is to provide a framework to evaluate construction phase performance and present a performance management plan using road construction information. Also, This study conducted time adjustment between the start and the finish of the project and developed performance metrics based on absolute and relative indicator. This study analyzed the cost, schedule, and changes of the road project construction process, showing the possibility of advancement of performance assessment and how to use it when planning new road construction projects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.240-247
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• 2020

The Korean military is having difficulty maintaining combat power due to the insufficient troop numbers caused by a demographic cliff and the reduction of the mandatory military service period. Recently, discussions on improving the military training system have increased significantly. This paper proposes an optimization model to establish military training schedules to improve combat power. The oblivion and learning effects on training tasks were quantified through a survey and applied to the model. The objective value, combat power, was calculated based on the total task scores of the unit members and the number of task failures after four weeks. The scenarios were configured by the change in educational conditions and initial scores of some tasks. As a result of scenario experiments, combat power has increased by at least 10% and up to 77%, which is sufficient to maintain combat power considering the change in troops. In addition, the planning of combat skill tasks has a significant impact on combat power. Through this research model, it is expected that military training managers will be able to establish a training schedule that maintains or improves the combat power of troops effectively.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.22-31
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• 2018

Due to the inherent risk factors of the remodeling projects, the remodeling project is failing frequently, and schedule delay are occurring in most remodeling projects. The risk factors that cause the delays in these remodeling projects are not common to all remodeling projects, and the likelihood of risk factors will be affected by the various characteristics of the project. In this context, based on the results of a reliable survey conducted on 29 construction managers who have performed remodeling projects, this research analyzes (1) "importance of each characteristic", which means how frequently the characteristics of the remodeling project affect the occurrence of risk factors, (2) "the likelihood of delay risk factors for remodeling projects", which assesses which risk factors are most likely to occur, and 3) "the level of effect of project characteristics that affects the occurrence of each risk factor." Through this study, the relationship between various characteristics of the office building remodeling projects and the delay risk factors was analyzed in various aspects, in further, it is expected that the owner planning the remodeling will be able to grasp the delay risk that is likely to occur according to the characteristics of the project in advance.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.39-53
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• 2004

Data production systems are generally very large, distributed and complex systems used for creating advanced (mainly statistical) reports. Typically, data is gathered periodically and then subsequently aggregated and separated during numerous production steps. These production steps are arranged in a specific sequence (workflow or production chain), and can be located worldwide. Today, a need for improving and automating methods of supervision for data production systems has been recognized. Supervision in this context entails planning, monitoring and controlling data production. Two significant approaches are introduced here for improving this supervision. The first is a 'closely-coupledd' approach (meaning direct communication between production jobs and supervisory tool, informing the supervisory tod immediately about delays in production) - based upon traditional production planning methods typically used for manufacturing (goods) and adopted for working with data production. The second is a 'loosely-coupled' approach (meaning no direct communication between supervisory tool and production jobs is used) - having its origins in proven traditional project management. The supervisory tool just enquires continuously the progress of production. In both cases, dates, costs, resources, and system health information is made available to management. production operators and administrators to support a timely and smooth production of periodic data. Both approaches are theoretically described and compared. The main finding is that, both are useful, but in different cases. The main advantages of the closely coupled approach are the large production optimisation potential and a production overview in form of a job execution plan, whereas the loosely coupled method mainly supports unhindered job execution and offers a sophisticated production overview in form of a milestone schedule. Ideas for further research include investigation of other potential approaches and theoretical and practical comparison.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.5-12
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• 2008

The construction of Pusan National University Yangsan Hospital is a new construction of a medical town in Yangsan. It is a case that CMr participated in the project from planning to post-completion. It shows an actual proof of Construction Management business applied CM by each phase. In this case, CMr selected the design-build contractor in the planning phase and technically performed CM businesses in every single phase such as design and construction schedule management regarding application of Fast Track technique, procurement management and contract administration in phases based on the Fast-tract; technique, design review, VE in the design phase, change order management in the construction phase and operating and maintenance in the post-construction phase. This study would go far toward applying CM to Mega Turnkey projects by analyzing the problems of CMr's practical application to the project and providing guidelines for effective and efficient CM business implementation especially in the Turnkey projects.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.419-423
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• 2008

The necessity of specialized and systematic management has been a tendency to accomplish the goal of business efficiently according the trend of construction industry has become bigger, complicated and specialized as well as Placing an order of CM(Construction Management) Service has been Increased because it made viable and positive effect. Institutional plan is necessary CM application from planning, realistic estimation of CM service charge, converting understanding among paticipants for the business and inducing specialization through certifyizing CM qualification to develop CM. But, it makes some realistic and unexpected pro41ems in the middle of step-by-step CM management for doing its business. So we need to consider a measure. This study suggests problems in practical a)fairs and improved idea that it summarized each stage of a bid for CM, planning, construction contract. It shows direction to take root successfully and develop.

• Journal of Intelligence and Information Systems
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• v.7 no.1
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• pp.1-15
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• 2001

Recently, Internet based Electronic Commerce is recognized as one of the alternatives for strengthening sales power of small and medium companies. However, small and medium manufacturers can't adjust properly to the new environment because they are in short of money, personnel, and technology. To cope with this problem, this paper deals with the development of virtual manufacturing agent to support sales agent. The sales activity of most of parts manufacturing companies is based on orders of buyers. The process of promotion, receipt and selection of orders of the parts manufacturing is closely coupled with the load status of the production lines. On deciding whether to accept an order or not, as well as negotiating with buyers, sales person needs information such as load and schedule of production lines, manufacturability of the order. Therefore, the functions of virtual manufacturing agents manufacturability analysis, process planning, and scheduling are key features in developing an agent of sales activity for the parts manufacturing business. While most of research on virtual manufacturing system so far is focused on the simulation of each product, this paper deals with the development of agent assisting internet-based product sales by supporting production information promptly. The pilot system of virtual manufacturing agent is implemented using KQML-based agent template and Java-based expert system shell for a small molding company.

• The Journal of Information Systems
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• v.10 no.1
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• pp.27-50
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• 2001

The purpose of this study was to examine some of the most important factors for the development of information systems with today's fast-paced, ever-changing, and exciting information system environment. Especially, it was focused to investigate current information technology related to develop information systems, to find some important problems during the development process, and to suggest solutions for the problems. Case research methodology was used because a natural setting was needed and a focus was on contemporary events for this study. Similarly, research phenomena was not supported by a strong theoretical base. The case was the development of an integrated information systems in a specific university. Multiple-case designs were desirable, but single-case study was used because of limitations of site selection. Multiple data collection methods were employed in this study such as documentation, interviews, and direct observation. Some major problems were found during the system development. First, the schedule to complete a project was delayed over six months. Second, the system did not ensure to align organizational goals and information systems goals based on BPR (Business Process Reengineering). Third, there was a difficulty in evaluating request for proposal (RPR) returns and choosing a vendor. Finally, information technology is changing too fast. So, it was very difficult to get the transparency of new technology The study has suggested a few solutions: top management support, matching If planning with business planning, complete project plan and control, user participation, and training Finally, joint application development (JAD) is strongly recommended, which is a workshop that unites management, IT specialists, and knowledge workers to define and specify the logical requirements and technical alternatives for a proposed system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.210-215
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• 2004

In can occur to many problems on progressing step without close scope definition, interrelation definition between activities, resource plan, and schedule plan on planning step. But it have not closely defined performance system on planning step because of many constraints of domestic construction industry. Therefore this paper intends to discuss a method of calculating optimal cost and duration using Linear Programming that solves maximing or minimizing problems among decision making methodology and Monte Carlo Simulation that decreases to probability errors. With outcoms applying Linear programming and Monte Carlo Simulation for calculating optimal cost and duration, follow as : With outcomes applying Monte Carlo Simulation, it could calculate reliable estimator about project duration through removing various constraints. With outcomes applying Linear programming, it could calculate optimal value about project cost through defining various variables and constraints on many activities.